Which bounties post. Never empty; every type by default.
Role pinged on a new bounty, or null for no ping. An edit never pings.
"Toggle Notification" on bounty posts: a button members press to give themselves the ping role, or remove it. On unless switched off. Never shown when the ping is
Premium Plus: the identity bounties post with. Null = the bot (and always null without Premium Plus).
Where bounties post. Null = not set; nothing posts until it is.